One of the greatest challenges to successful treatment of cancers lies in early detection and staging. A novel imaging device is proposed to allow rapid, high quality imaging of the bladder and other endoscopically accessible organs. This instrument will be based on the principles of optical coherence tomography (OCT) to achieve micron-scale resolution over an imaging depth of up to several millimeters. Preliminary studies have shown that OCT can distinguish normal and cancerous bladder tissue. The proposed parallel optical coherence tomography (IIOCT) device represents a fundamental advance over existing OCT systems because it implements a parallel imaging approach with integrated arrays of optoelectronic sources, detectors, and specialized micro electronic processing and control systems. This allows rapid image acquisition (30 frames per second or greater) with inexpensive, low power light sources. The emitted and detected light is carried through a small (2mm) fiber bundle, eliminating the need for mechanical scanning at the distal end of the probe. A reduction in imaging system size and cost will be realized. The proposed design utilizes semiconductor manufacturing techniques to condense electro-optical and signal processing stages on a specialized microchip, which could be mass produced. Thus, the entire OCT system could potentially be housed in a small, lightweight box with a detachable probe. An inexpensive, portable system would allow greater patient access to this diagnostic modality. The specific aims of this proposal are: 1. Design and fabricate special optoelectronic and optical components for a OCT system. The considerable optoelectronic expertise and fabrication facilities at the University of Arizona will be recruited to create the sources, detectors, and signal processing electronics needed for this effort. 2. Fabricate electronics and integrate components into a miniaturized package. Optoelectronic and optical components will be integrated with the multi-fiber bundles used in the interferometer and endoscopic probe. 3. Assemble and test two II OCT Systems. A 10 parallel channel system will be created and interface software written. Feedback on probe design and user interface will be sought during animal and human studies and incorporated into the final, 100 parallel channel system. 4. Determine the ability of the I I OCT system to accurately determine the stage of transitional cell carcinoma of the bladder. A series of studies will be performed to determine the value of OCT in distinguishing between normal bladder tissue, carcinoma in situ (Tis), and cancer confined to mucosa (Ta) lamina propria (Ti) and muscle (T2).